Abstract: In a line by line image forming apparatus, line switching information which depends on scan line curve and an overlap data length to be read that overlaps across a plurality of lines before and after a switching position instructed by line switching information are set in a register. If switching to the line above or below is instructed by the line switching information, an address generating unit, when reading image data from an image memory, generates the read address and read data length of the image memory in accordance with the line switching information and the overlap data length, and reads image data corresponding to a current line and the line above or below the current line in accordance with the generated data.

Abstract: In a line by line image forming apparatus, line switching information which depends on scan line curve and an overlap data length to be read that overlaps across a plurality of lines before and after a switching position instructed by line switching information are set in a register. If switching to the line above or below is instructed by the line switching information, an address generating unit, when reading image data from an image memory, generates the read address and read data length of the image memory in accordance with the line switching information and the overlap data length, and reads image data corresponding to a current line and the line above or below the current line in accordance with the generated data.

Abstract: To accurately setting a print charge on the basis of a color which is used actually at a stage to print data consisting of a mixture of color data and monochromatic data. It is possible to judge a color designated for printing by detecting color information from drawing processing information converted from the data and storing color designation information on the basis of the detected color information. Accordingly, a printing system is capable of setting a print charge accurately on the judged color.

Abstract: To accurately setting a print charge on the basis of a color which is used actually at a stage to print data consisting of a mixture of color data and monochromatic data. It is possible to judge a color designated for printing by detecting color information from drawing processing information converted from the data and storing color designation information on the basis of the detected color information. Accordingly, a printing system is capable of setting a print charge accurately on the judged color.